1. Field of the Invention
The invention is related to the field of communications, and in particular, to communication networks that provide wireless access to communication services.
2. Description of the Prior Art
User demand for wireless access to communication services is rapidly growing. In a typical wireless access scenario, a user operates a wireless communication device to exchange wireless communication signals over the air with a wireless access point. The wireless access point exchanges the user communications with a service center over a communication network. The service center processes the user communications to provide a service, such as telephony communication, Internet access, or video streaming.
Examples of wireless communication devices include mobile telephones, personal digital assistants, and laptop computers. Examples of wireless access points include base stations, WIFI hotspots, and antenna systems. Examples of service centers include mobile switching centers, Internet access points, and media servers. Examples of wireless formats include CDMA, WIFI, and WIMAX.
As the user demand for wireless access to communication services has increased, so has the deployment of wireless access points. Various communication networks have been developed to exchange user communications between the growing number of wireless access points and the service center. Unfortunately, these communication networks have not been optimized for both efficiency and reliability.
FIG. 1 illustrates an example of a prior communication network that exchanges user communications between wireless access points and a service center (the wireless access points use the acronym WAP on the figures). Note that groups of proximate wireless access points are coupled in series to form a serial route to the service center. Each wireless access point has a point-to-point communication link to the service center in the serial route.
For example, wireless access points A, B, and C each have their own point-to-point communication link to the service center that follows the serial route. If there is a fault (indicated by an “X” mark on the figures) on the serial route between wireless access point B and wireless access point C, then the point-to-point communication links from wireless access points A and B to the service center are lost.
FIG. 2 illustrates another example of a prior communication network that exchanges user communications between wireless access points (WAPs) and a service center. Note that the service center is now coupled to a central communication ring. Also note that groups of proximate wireless access points are coupled to collector communication rings. Each collector ring is coupled to the central ring through a ring node. Thus, the wireless access points communicate with the service center over the collector rings and the central ring.
Each wireless access point has a point-to-point communication link over the rings to the service center. For example, wireless access point B has a point-to-point communication link to the service center through wireless access point C and ring nodes E and F (B-C-E-F-SC). For back-up in the event of a fault, wireless access point B has a second point-to-point link to the service center through wireless access point A and ring nodes E and D (B-A-E-D-SC).
For a fault on the collector ring between wireless access point B and wireless access point C, wireless access point B and the service center would switch user communications from the failed first link (B-C-E-F-SC) to the operational second link (B-A-E-D-SC). Likewise, for a fault on the central ring between ring node E and ring node F or between ring node F and the service center, wireless access point B and the service center would switch user communications from the failed first link (B-C-E-F-SC) to the operational second link (B-A-E-D-SC).
Unfortunately, there are still problems with the prior communication network of FIG. 2. If a ring node fails, then the wireless access points that are served by the failed ring node cannot communicate with the service center. For example, if ring node E fails, then wireless access points A, B, and C cannot communicate with the service center over any of the point-to-point communication links.
In addition, the point-to-point links typically have a dedicated amount of bandwidth that goes unused—especially on the back-up links. Thus, the point-to-point links between the wireless access points and the service center represent an inefficient use of bandwidth.